Field of the Invention
The invention relates to a method for automatically feeding printing plates to and removing them from a printing press, which includes inserting the leading edge of the respective printing plate into a leading-edge clamping device and clamping the leading edge therein, and forwardly rotating the plate cylinder so as to wind the printing plate thereon.
The invention relates, furthermore, to a method for automatically removing a printing plate from the plate cylinder of a printing press, which includes opening a trailing-edge clamping device, and rotating the plate cylinder backwards so as to unwind the printing plate and, simultaneously, sliding it in a direction of a removal position.
The invention relates, moreover, to a device for performing the first-mentioned method, the device having an infeed or draw-in shaft for inserting a printing plate therein, and having a plate cylinder with an automatically actuatable leading-edge claping device.
Finally, the invention relates to a further device for performing the second-mentioned method, the further device having a plate removal or draw-out shaft, a plate cylinder with an automatically actuatable leading-edge and trailing-edge clamping device, and a control that, in order to remove a printing plate, opens the trailing-edge clamping device and slides the printing plate trailing edge into the plate removal or draw-out shaft by a backwards rotation of the plate cylinder.
Methods and devices of this general type have become known heretofore from the published German Patent Documents DE 41 30 359 A1 and DE 195 08 844 A1. The subjects of both publications propose, for the feeding and removal of the printing plates, transport devices which, during the feeding of the printing plates, convey them into the leading-edge clamping device and, during the removal of the printing plates, transport them out of the leading-edge clamping device. The transport devices which are proposed are lifting suckers which are arranged on displaceable carriers and transport the printing plates with the aid of drives. A disadvantage of these transport devices is that they are complicated, expensive and susceptible to failure.